Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Direct current (DC)-to-alternating current (AC) power inverters may include a passive filtering circuit. The filtering circuit may include an inductor and/or a capacitor (e.g., an LC circuit). Inductors configured for switching operation below 1 MHz may utilize a ferromagnetic or magnetic core. However, power inverters (e.g., GaN switches) operating at higher switching frequencies (e.g., 5-10 MHz), may need smaller inductance values. As such, air-core inductors are feasible for use in conventional power inverters. Among other features, when operated at high frequency, air-core inductors may offer lower cost and higher efficiency as compared to other inductor configurations. Furthermore, printed circuit board (PCB) embedded air-core inductors provide the potential benefit of miniaturization and integration with power electronic circuitry.
Various structures have been proposed for both embedded and non-embedded air-core inductors. For example, solenoid, spiral, and toroidal configurations are the most common inductor structures. Inductors with a toroidal configuration may provide a potential benefit of reduced electromagnetic interference (EMI) as compared to other alternative configurations.